This invention relates to phased ray antennas, and more particularly, this invention relates to wideband phased array antenna elements with a wide scan angle.
The development of wideband phased array antenna elements are becoming increasingly important in this telecommunications era when the frequencies in communications range from a minimum of 2 GHz to 18 GHz. Some of these applications require dual polarization antenna elements, a scan angle range of +/xe2x88x9245 degrees with low scan loss, and a low loss, lightweight, low profile that is easy to manufacture and uses power in the multiple watts range.
Currently, the common problem of obtaining a wideband phased array antenna with a wide scan angle and reasonable power handling is being solved by various methods. These methods include the use of an antenna and system that divides the frequency range into two or more bands, which results in considerable more mass and volume plus a radio frequency interface problem. Other methods include an antenna structure using a mechanical gimbal to obtain the required scan angle. This type of antenna element and system again results in more mass, volume, and slow response time. The development of space qualified materials and analysis tools, however, could contribute to new solutions to this problem.
The present invention is advantageous and provides a phased array antenna element that includes an antenna support and longitudinally extending radiating leg elements supported by the antenna support and flared outward in a v-configuration from a vertex to antenna element tips. A resistive element is positioned on each radiating leg element and has a resistive value along the radiating leg elements from a low loss at the vertex to a high loss at the antenna element tips. Each resistive element is formed from a plastic film and includes a plurality of overlapping strips. The radiating leg elements are formed from a foam material, in yet another aspect of the present invention, and curved outward along their length. They form a triangular configuration and can have a height that is about three times greater than the base.
The antenna support can comprise a support plate that is horizontally positioned relative to the radiating leg elements and include orifices for receiving attachment fasteners and attaching the phased array antenna element onto a mounting surface. Each radiating leg element includes an inside edge on which the resistive element is positioned.
In yet another aspect of the present invention, four radiating leg elements are spaced 90xc2x0 apart from each other and form an antenna having dual polarization.
A radio frequency coaxial feed input can be mounted on the antenna support and a metallic strip feed can interconnect radio frequency coaxial feed input and resistive elements. In still another aspect of the present invention, a 0/180xc2x0 hybrid circuit can be connected to the radio frequency coaxial feed input.